Bone grafting, in the field of orthopedics, refers to natural or synthetic bones transplanted into the diseased or damaged site to help promote re-generation of new bone. The efficacy of bone grafts is based on at least three concepts: osteogenesis, osteoinduction, and osteoconduction. Osteogenesis is defined as the ability to produce new bone, and is determined by the presence of osteoprogenitor cells and osteogenic precursor cells in the area. Both fresh autografts and bone marrow cells contain osteogenic cells, although often in decreased numbers in the elderly patient (Helm G A, Dayoub H, and Jane J A Jr, Neurosurg Focus, 10(4), E5, 2001).
Osteoconduction is defined as the ability of bone to grow on a surface or structure. Osteoconductive properties may be determined by the presence of a structure (scaffold) that allows for vascular and cellular migration, attachment, and distribution (Helm G A, Dayoub H, and Jane J A Jr, Neurosurg Focus, 10(4), E4, 2001). These osteoconductive properties may be altered by structure, pore size, and porosity of the scaffold. (Helm et al., Neurosurg Focus, 10(4), E4, 2001.) Osteoconduction may be achieved through the use of autografts, allografts, DBM (demineralized bone matrix), hydroxyapatite, and collagen. Osteoinduction is defined as the ability to stimulate stem cells to differentiate into mature bone forming cells through stimulation by local growth factors (Subach B R, Haid R W, Rodts G E, et al., Neurosurg Focus, 10(4):Article 3, 2001). Bone morphogenetic proteins and DBM are the most potent osteoinductive materials, although allo- and autografts have some osteoinductive properties (Kalfas I H, Neurosurg Focus 10(4), E1, 2001). Improving the processing and administration of an oxygenated DBM composition will improve the osteogenesis, osteoconduction, and osteoinduction capabilities in bone grafting to advance the state of the art in bone repair.